Significant differences were found in the concentrations of total nitrogen, nicotine, potassium, and calcium in the cured leaf of burley tobacco among different sources and rates of nitrogen fertilizer, and different methods of application. Differences among years were as large as, or larger than differences among treatments. Total nitrogen and nicotine increased with increasing rates of nitrogen fertilization while potassium concentrations decreased slightly. Changes in calcium concentration were less consistent but calcium tended to decrease as potassium concentration increased or as nitrogen decreased. Only the first 75 pounds of nitrogen resulted in an increase in yield.

(Full article published with kind permission from "Tobacco International")